Syngas or synthesis gas is a mixture comprising hydrogen and carbon monoxide along with small quantities of carbon dioxide, methane, and other trace gases. Syngas is normally produced from a feedstock hydrocarbon, such as natural gas, liquefied petroleum gas, naphtha, and residual oil. Syngas can be used directly or may be converted to other gaseous, liquid, or solid products, such as industrial gases, alcohols, transportation fuels, ammonia, urea, etc. Syngas can be used in a gas-to-liquid (GTL) process using a Fischer-Tropsch process to rearranges the carbon and hydrogen molecules to produces a liquid hydrocarbon molecule that can be used as a fuel or blend stock, for example.
Syngas is produced by gasification of the feedstock. Existing gasification processes for generating syngas include, for example, steam reforming, autothermal reforming, pyrolysis, and partial oxidation. Existing methods for generating syngas create challenges such as controlling the hydrogen/carbon monoxide ratio, providing sufficient water (steam reforming) or oxygen (partial oxidation), providing catalysts, and managing high temperatures generated in the processes.
Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane. Natural gas is used as a source of energy for heating, cooking, and electricity generation. It may also be used as feedstock in the manufacture of liquid fuel using a GTL process. There is an abundance of natural gas in undeveloped fields, capped wells, and storage tanks. Existing GTL processes are not economical for use in converting natural gas to liquid fuels due to the high capital and operating costs to process natural gas at the widely-distributed locations.